title: Quantitative variation analysis of fetal DNA in maternal plasma samples collected before and after amniocentesis.
abstract: OBJECTIVE
  The aim of this study was to evaluate possible procedure-related variations in the levels of cell-free fetal DNA (fDNA) in maternal plasma of women undergoing genetic amniocentesis.
  
  
  METHODS
  Blood samples were collected at 16-18 weeks' gestation from 33 pregnant women attending the Fetal Medicine Unit for genetic amniocentesis. For each woman, two blood samples were obtained: the first immediately before amniocentesis and the second one 15 min after the procedure. A real-time quantitative polymerase chain reaction assay, using primers for SRY and beta-globin genes, was used to assess fDNA concentrations in maternal plasma. A Wilcoxon signed-rank test was used for statistical analysis.
  
  
  RESULTS
  The karyotype on cultured amniocytes showed that 15 out of 33 women had a male fetus. Real-time quantitative polymerase chain reaction results, on maternal plasma sample pairs from known male pregnancies, showed no significant variations of fDNA correlated to amniocentesis (P=0.394).
  
  
  CONCLUSIONS
  Our preliminary study suggests that amniocentesis, although invasive, could be associated with minimal, if any, disruption at the fetal-maternal interface, as revealed by the lack of substantial modifications of fDNA levels in maternal circulation.
authors.affiliation: Department of Gynecology, Perinatology and Human Reproduction, University of Florence, Florence, Italy. ceciliabussani@yahoo.it
authors.forename: Cecilia
authors.initials: C
authors.lastname: Bussani
authors.forename: Mariarosaria
authors.initials: M
authors.lastname: Di Tommaso
authors.forename: Riccardo
authors.initials: R
authors.lastname: Cioni
authors.forename: Lucia
authors.initials: L
authors.lastname: Pasquini
authors.forename: Laura
authors.initials: L
authors.lastname: Quitadamo
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Scarselli
mesh_terms: D000649:Amniocentesis / Q000009:adverse effects*; D000653:Amniotic Fluid / Q000166:cytology / Q000378:metabolism; D041322:Chromosomes, Human, Y / Q000378:metabolism*; D004247:DNA / Q000097:blood*; D005260:Female; D006801:Humans; D059785:Karyotype; D008431:Maternal-Fetal Exchange; D011247:Pregnancy; D011262:Pregnancy Trimester, Second
chemical_list: D004247:DNA